The present invention relates generally to a mixing signal-path setting apparatus and mixing signal-path setting program for setting signal paths for a system that mixes signals of a plurality of channels. The present invention is particularly suitable for application to audio mixers that mix audio signals of a plurality of channels after processing the audio signals.
The audio mixers (audio mixing systems) are constructed to mix audio signals (e.g., voice signals and/or tone signals) of two or more input channels, designated by a human operator from among a plurality of input channels, and then output the thus-mixed audio signals to output channels designated by the human operator from among a plurality of output channels.
The conventional audio mixers for use in broadcasting studios have a so-called “mix-minus” function. Announcer inputs his or her voices to a microphone while monitoring sounds having been mixed together. However, if the announcer is away from the installed position of the audio mixer, the announcer would feel it difficult to speak because, in such a case, his or her voices are heard with considerable time delays. Thus, the above-mentioned “mix-minus” function is used to allow the announcer to monitor sounds with only his or her voices excluded therefrom.
Also, as regards audio mixers used mainly in halls (e.g., auditoriums) and event venues (sites), use of the “mix-minus” function can solve a similar problem, for example, in a case where they are used for broadcasting purposes.
Generally, the conventional audio mixers for use in broadcasting studios perform the “mix-minus” function using a dedicated circuit that subtracts signals of announcer's voices from signals having been temporarily mixed together completely. Therefore, the conventional audio mixers are disadvantageous in that they separately require the dedicated circuit and in that signals output from the audio mixers tend to have quality degradation or deterioration.
The conventional audio mixers used in halls and event venues, on the other hand, include a multiplicity of signal input and output terminals. Therefore, these audio mixers have a highly-flexible signal path setting function for coupling the input channels to the output channels. So, there have been studied more sophisticated approaches for implementing the mix-minus function using the signal path setting function.
FIG. 5 is a system block diagram of an audio mixer conventionally used in a hall or event venue. In the figure, components not pertinent to the present invention are omitted for simplicity.
In FIG. 5, reference numeral 51 represents a microphone input card, which includes analog input terminals for taking in analog signals from a microphone, a built-in head amplifier and an analog-to-digital (A/D) converter. 52 represents a line input card, which includes input terminals for inputting analog signals and an A/D converter. 53 represents a digital input card, which includes input terminals for inputting digital signals. Any desired one of or a desired combination of these input cards is mounted in a box. Throughout this patent specification, the term “card” means a card-type device having a built-in electronic circuit.
54 represents an input patch section, which selectively couples individual input signals from the above-mentioned cards to input channels of an input channel processing section 55. The input channel processing section 55 adjusts the sound volume, quality, etc. of the input signal of each of the input channels, and selectively couples the input signals, before or after the adjustment of the sound volume, quality, etc., to given buses of a mixing bus unit or stereo bus unit 57. For example, the mixing bus unit 56 includes buses MIX1 to MIX48, and the stereo bus unit 57 includes buses STEREO L and STEREO R.
Mix output channel processing section 59 is connected with corresponding buses of the mixing bus unit 56. The processing section 59 receives mixed results of the signals of the input channels coupled to the corresponding mixing buses, then adjusts the sound volume, quality, etc. of the mixed signals, and outputs the thus-adjusted mixed signals to an output patch section 60. Stereo output channel processing section 58, on the other hand, is connected to corresponding buses (STEREO L and STEREO R) of the stereo bus unit 57. The stereo output channel processing section 58 receives mixed results of the input signals of the input channels coupled to the corresponding stereo buses, then adjusts the sound volume etc. of the mixed signals, and outputs the thus-adjusted mixed signals to the output patch section 60.
The mixing buses MIX1 to MIX48 correspond to the mix output channels, while the stereo buses STEREO L and STEREO R correspond to the stereo output channels.
The output patch section 60 selectively supplies the output signals from the mix output channel processing section 59 and stereo output channel processing section 58 to given ones of succeeding output terminals. Reference numeral 61 represents an analog output card which includes a digital-to-analog (D/A) converter and analog output terminals. 62 represents a digital output card which includes digital output terminals.